Low colorectal anastomoses. An experimental assessment of two sutured and two stapled techniques

Extraperitoneal colorectal anastomoses were constructed in dogs by four methods: one layer of sutures (N=10), two layers of sutures (N=10), EEA staples (N=10), and SPTU staples (N=10). Dehiscence occurred in eight sutured and one stapled anastomosis (P<0.05). The four leaks following two layer sutured anastomoses caused three deaths, whereas all four leaks following one-layer sutured anastomoses were only detected radiologically (P<0.02). In the stapled group, the single leak followed EEA anastomosis and was fatal. Anastomotic narrowing was greater in sutured than stapled groups (P<0.05). Two layers of sutures produced gross narrowing compared with one layer (P<0.002). Two rows of staples (EEA) produced more narrowing than one row (SPTU) (P<0.01). Mean hydroxyproline concentrations and bursting pressures on the seventh postoperative day were higher in stapled than sutured anastomoses (P<0.05). Submucosal alignment, mucosal continuity, tissue viability, and stage of healing were all inferior for two-layer sutured anastomoses, reaching statistical significance for tissue viability (P<0.05). Stapled anastomoses were completed significantly faster (32.6±7.3 minutes) than sutured (54.1±8.4 minutes) (P<0.01). This experimental study has demonstrated that stapling is a fast and reliable method of colorectal anastomosis with a low complication rate. The shortcomings of the standard two-layer sutured anastomosis are discussed.